Long-term impact of moscow heat wave and wildfires on mortality.

displacement. to estimate the difference between the observed and the expected number of daily deaths during and after the heat wave, a predictive model was developed, as described in eAppendix (http://links.lww.com/EDE/A874). We also used the annual mortality data from neighboring Saint Petersburg for comparison (eFigure 1, http://links.lww.com/ EDE/A874).7 the Figure shows observed and expected deaths between 2009 and 2012 in Moscow. A major deficit in mortality occurred from the beginning of October until the end of the year of the heat wave. the deficit seemed to continue during 2011, after which there was an excess mortality in 2012. the cumulative excess mortality is illustrated in eFigure 2 (http://links.lww.com/EDE/A874). Non-accidental cumulative excess mortality reached its maximum of 11,300 (95% confidence interval [CI] = 10,800– 11,800) almost 2 months after the end of the heat wave. A prolonged period of steady decline in cumulative excess mortality continued for 15 months after this date until the end of 2011, when the minimum of 5800 (1500–10,100) deaths was recorded. the mortality displacement during this period was 49% (95% CI = 11%–87%). In other words, about one-half of all excess deaths during the heat wave were forward-displaced for the period ranging from 2 to 17 months. Since January 2012, cumulative excess mortality began to increase again and the magnitude of harvesting diminished to 14% (0%–67%) by the end of 2012. Stratified analyses showed that the ratio of deaths among those aged 60 and over relative to those below 60 peaked during the heat wave and did not return to the pre-heat wave levels during 2012 (eFigure 3, http://links.lww. com/EDE/A874). the ratio of cardiovascular to non-cardiovascular mortality also increased during the heat wave, but showed a gradual decrease compared with the period before the heat wave. this indicates that the increase in deaths in 2012 was due to causes other than cardiovascular causes. In conclusion, marked mortality displacement was observed as a result of the 2010 heat wave in Moscow. this amounted to around half of all excess deaths during the heat wave; this displacement occurred mainly within few months, but extended for a longer period. the excess mortality observed after about 18 months following the end of the heat wave may indicate persistent long-term effects of the heat wave and smog episode, but it could also result from inaccurate projections of expected deaths.